Merce Cunningham’s death in 2009 extinguished a great light in American arts; he was truly a national treasure, though hardly a household name. As part of that world-shaking generation of post-WWII giants of the avant garde, he changed the face of dance forever by liberating it from mere pantomime – essentially asking, why must a dancer act out a fairy tale? Can we not appreciate movement for movement’s sake? After this radical break with narrative, Cunningham’s practice mirrored or was influenced by his partner, iconoclastic composer John Cage, in introducing “chance operations” – guided improvisation – to dance, at the same time improvisation was blossoming in music. Ann Sorvino, esteemed choreographer and erstwhile member of Cunningham’s company, introduces this film at the Southeast Museum of Photography in conjunction with her work with the Surfscape Contemporary Dance Theatre. Split Sides, directed by Charles Atlas, is an excellent record of Cunningham’s chance operations, with various alternate elements (not just the choreography) chosen by an onstage roll of the dice. In addition to choices of lighting, set and costume designs, there are two scores: one by Radiohead, one by Sigur Rós. – Jessica Bryce Young(2 p.m. at Southeast Museum of Photography, Daytona State College, 1200 W. International Speedway Blvd., Daytona Beach; free; 386-506-4475; smponline.org)